The Neutron Star Crust: Nuclear Physics Input

TL;DR

This paper develops a self-consistent model of the neutron star inner crust using nuclear physics inputs, analyzing how uncertainties in nuclear matter properties influence crust composition and pressure.

Contribution

It provides a comprehensive, self-consistent model of the neutron star inner crust based on nucleonic equations of state, exploring the impact of nuclear physics uncertainties.

Findings

Crust composition and pressure are sensitive to symmetry energy and low-density neutron matter.

Non-monotonic dependence of crust nuclei size on symmetry energy.

Future experiments and observations can constrain nuclear physics inputs.

Abstract

A fully self-consistent model of the neutron star inner crust based upon models of the nucleonic equation of state at zero temperature is constructed. The results nearly match those of previous calculations of the inner crust given the same input equation of state. The extent to which the uncertainties in the symmetry energy, the compressibility, and the equation of state of low-density neutron matter affect the composition of the crust are examined. The composition and pressure of the crust is sensitive to the description of low-density neutron matter and the nuclear symmetry energy, and the latter dependence is non-monotonic, giving larger nuclei for moderate symmetry energies and smaller nuclei for more extreme symmetry energies. Future nuclear experiments may help constrain the crust and future astrophysical observations may constrain the nuclear physics input.